When my teacher was talking about this, I realized that this is the same thing we do in the church. Many of our youth see that even the leaders in the church had a chance to "live a little" as teens. They see the leaders sin as a cool testimony and want one of their own. Many times the youth are being lead astray by the idea of witnessing.
My teacher also talked about how the program would be better suited to a prison program. It would help to encourage rather then prevent. In the same way, I think testimonies or important. The Bible talks about how we should give our testimonies. However, a testimony is simply a public avowal. Therefore it’s not necessarily "how you became a Christian” but rather what God is doing in your life. If a person's testimony it’s continually changing then I think that could be a problem.